The present invention relates to a camera capable of standard and close-up exposures.
For close-up photography, a camera such as a single-lens reflex camera of the type which can use interchangeable lenses, extension bellows, extension tubesets or magnifying lenses have been generally used so that the photographic lens can be further extended from the camera body toward a minute subject depending upon a desired magnification. In order to take pictures of subjects magnified by microscopes, special adapters have been used. With cameras other than single-lens reflex cameras, the optical systems for photography or exposure and viewing are very closely spaced apart from each other in the case of close-up photography so that focusing as well as correction of parallax becomes very difficult. Therefore, a special adapter must be provided for respective cameras.
Extension bellows are very expensive and when an extension bellows is mounted, the camera becomes so bulky that it becomes difficult to operate the camera in the field; i.e., the camera lacks mobility. When a magnifying lens is attached, the camera is still compact in size and very easy to operate, but there exists a disadvantage in that the magnification cannot be varied at all.
Extension bellows and magnifying lenses have a common defect in that standard exposures are impossible with an extension bellows or a magnifying lens attached. As a result, the extension bellows or magnifying lens must be removed for standard exposures and again attached for close-up exposures, which is very cumbersome.
From the standpoint of focusing and framing, single-lens reflex cameras are very advantageous in that a subject can be directly viewed through a photographic lens so that they are increasingly used for close-up exposures. However, with the conventional close-up attachments, the single-lens reflex cameras become so bulky that their portability is adversely affected in the field as described above. In addition, the combination of a single-lens reflex camera and a close-up attachment becomes very expensive as described above.
In close-up exposures, exposure factors must be adjusted every time an exposure is made because minute subjects are not uniformly and brightly illuminated by ambient or natural light. Furthermore, the higher the magnification, the less brilliant the image becomes so that with dim ambient light, it becomes extremely difficult to focus and frame a minute subject and to attain a correct exposure.
Anyone can observe a magnified image of a minute subject through a microscope or a magnifier in a very simple manner, but the exposure of this magnified image is not simple because of the reasons previously described.